What was terra nullius?

Terra nullius is the legal doctrine that British colonists applied to Australia from 1788 onwards, holding that the continent was uninhabited or that its Aboriginal inhabitants were too uncivilised to constitute a society with property rights. The doctrine justified British claims to sovereignty and the granting of land to settlers without treaty or compensation. It was overturned by the High Court of Australia in the 1992 Mabo decision.

The doctrine drew on European international law as it had developed from the sixteenth century. International lawyers including Hugo Grotius (1583 to 1645) had argued that European powers could claim territory by discovery, settlement, or conquest, with terra nullius (literally 'land belonging to no one') the basis for claims to territory occupied only by indigenous peoples whose societies the Europeans did not consider sufficiently developed.

The doctrine had specific Australian application. The British government's instructions to Captain Cook in 1768 had directed him to take possession of any uninhabited country he discovered or, if inhabited, to do so 'with the consent of the natives'. Cook's 1770 claim of the east coast at Possession Island was made without Aboriginal consent. The British government's instructions to Captain Phillip in 1786 directed him to live in friendship with the Aboriginal people but did not require their consent for settlement. By the early nineteenth century, terra nullius had hardened into the settled legal doctrine that Aboriginal peoples had no land rights recognisable in Australian law.

Several twentieth-century challenges set the stage for the doctrine's eventual fall. The Yirrkala Bark Petitions of 1963, the 1971 Milirrpum v Nabalco case (which upheld terra nullius), the 1972 Aboriginal Tent Embassy, the Aboriginal Land Rights (Northern Territory) Act 1976 (which created statutory land rights in the NT regardless of common law), and decades of Indigenous activism built the pressure for change. Eddie Mabo's case, supported by the James Cook University law academic Henry Reynolds and lawyers Ron Castan and Greg McIntyre, was filed in 1982 and decided by the High Court on 3 June 1992. Justices Brennan, Deane, Toohey, Gaudron, Mason, and McHugh ruled (Dawson dissenting) that Aboriginal peoples had been treated unjustly by the doctrine and that native title could exist in Australian law where Aboriginal connection to country had been maintained. The doctrine of terra nullius was specifically rejected. The Native Title Act 1993 codified the decision and established the procedures for recognising native title across Australia. About 50 per cent of Australia is now subject to determined or claimed native title interests.